As depicted in FIG. 15, a heat exchanger, such as an air conditioner, is constructed by inserting heat exchanger pipes, in which a heating medium flows, into through-holes 11 in a fin stack 10 that has been produced by stacking a plurality of fins 9 in which the through-holes 11 are formed. Hairpin-shaped heat exchanger tubes 20, which are formed by bending copper pipes into U shapes at a central part thereof, are used as the heat exchanger pipes.
As depicted in FIG. 16, an insertion apparatus 5 is used to insert the hairpin-shaped heat-exchanger tubes 20 into the fin stack 10 (see FIG. 5 of Patent Literature 1).
The insertion apparatus 5 illustrated here has the fin stack 10 stacked in the up-down direction and inserts the hairpin-shaped heat-exchanger tubes 20 into the fin stack 10 by lowering the hairpin-shaped heat-exchanger tubes 20 from above.
Hairpin-shaped heat-exchanger tubes 20 that have been discharged from a bender, which is a pipe bending apparatus, are fed to the rear surface side of the insertion apparatus 5 and hang downward with a bent portion 21 in the center of each hairpin-shaped heat-exchanger tube 20 suspended on a rod 6.
The hairpin-shaped heat-exchanger tubes 20 that have been hung on the rod 6 are conveyed to an alignment apparatus 7 of the insertion apparatus 5. The alignment apparatus 7 has an inclined plate 8 whose upper surface is downwardly inclined toward the insertion position. The bent portion 21 in the center of each hairpin-shaped heat-exchanger tube 20 is disposed on the upper surface of the inclined plate 8, and the hairpin-shaped heat-exchanger tubes 20 automatically move toward the insertion position by sliding under their own weight.
A plurality of such inclined plates 8 are provided in the depth direction with respect to the plane of FIG. 16, with hairpin-shaped heat-exchanger tubes 20 stocked on each of the plurality of inclined plates 8.
The hairpin-shaped heat-exchanger tube 20 positioned at the bottom of each inclined plate 8 has its bent portion 21 clamped by a clamping apparatus 4 and is inserted into the fin stack 10.
The hairpin-shaped heat exchanger tubes 20 are discharged from a bender, which is a pipe bending apparatus, and the hairpin-shaped heat exchanger tubes 20 are conveyed to an insertion apparatus for hairpin-shaped heat exchanger tubes with the bent portions 21, which are the bent parts in the centers of the hairpin-shaped heat exchanger tubes 20, hung on a rod.